UNIT 2 Handout Part 1 Flashcards
1
Q
- contributes to homeostasis by protecting the body and helping regulate body temperature
- allows you to sense pleasurable, painful, and other stimuli in your external environment
A
integumentary system
2
Q
- Changes in skin color may also indicate _________ in the body.
- For example, the bluish skin color associated with ________ (oxygen deficiency at the tissue level) is one sign of heart failure as well as other disorders.
- Abnormal skin eruptions or rashes such as chickenpox, cold sores, or measles may reveal systemic infections or diseases of internal organs, while other conditions, such as warts, age spots, or pimples, may involve the skin alone.
A
- homeostatic imbalances
- hypoxia
3
Q
structure of the skin
A
skin
- epidermis
- dermis
- subcutaneous layer
4
Q
- Cutaneous membrane or integument
- Covers the external surface of the body.
- Largest organ of the body in both surface area and weight.
A
skin
5
Q
- superficial, thinner portion
- composed of epithelial tissue
A
epidermis
6
Q
- deeper, thicker portion
- composed of connective tissue
A
dermis
7
Q
- deep to the dermis but not part of the skin
- consists of areolar and adipose tissues
- function: serves as a storage depot for fat and contains large blood vessels that supply the skin
- contains nerve endings
- ________: sensitive to pressure
A
SUBCUTANEOUS LAYER OR HYPODERMIS
- pacinian (lamellated) corpuscles
8
Q
EPIDERMIS is composed of
A
a. keratinocytes (90%)
b. melanocytes (8%)
c. langerhans cells
d. merkel cells
9
Q
produce the protein _______
- tough fibrous protein that helps protect skin and underlying tissues from heat microbes and chemicals
- produce ______, which release a water repellent sealant that decreases water entry and loss and inhibits the entry of foreign materials
A
a. keratinocytes (90%)
10
Q
- develop from the ______ of developing embryo and produce the pigment ______
- yellow-red or brown-black pigment
- contributes to skin color and absorbs damaging ultraviolet (UV) light
A
b. melanocytes (8%)
11
Q
- arise from red bone marrow and migrate to the epidermis
- participate in immune responses mounted against microbes that invade the skin and are easily damaged by the UV light
- help other cells of the immune system recognize an invading microbe and destroy it
A
c. langerhans cells
12
Q
- located in the deepest layer of the epidermis
_________:
- a sensory neuron
- detect touch sensations
A
d. merkel cells
- merkel (tactile) disc
13
Q
Types of cells in the epidermis
A
- stratum basale
- stratum spinosum
- stratum granulosum
- stratum lucidum
- stratum corneum
14
Q
- deepest layer of the epidermis
- composed of single row of _______ or _______ keratinocytes
- some cells are ____ cells
- contents of the keratinocytes of stratum basale:
- nuclei are large
- cytoplasm contains many ribosomes
- small golgi complexes
- few mitochondria
- some rough endoplasmic reticulum
- cytoskeleton includes intermediate filaments
– _________: composed of protein that will from keratin in more superficial epidermal layers - ______ and ______ with their associated _______ are scattered among the keratinocytes of the basal layer
A
STRATUM BASALE
- cuboidal or columnar
- stem
- tonofilaments
- melanocytes and merkel cells; merkel discs
15
Q
- superficial to the stratum basale
- 8-10 layers of many-sided keratinocytes with bundles of tonofilaments
- thornlike spines
- langerhans cells and projections of melanocytes are also present in this layer
A
STRATUM SPINOSUM
16
Q
- middle of the epidermis
- consists of 3-5 rows of flattened keratinocytes that are undergoing ________: programmed cell death
- organelles are beginning to degenerate
- contains ________
- darkly staining granules of a protein
- converts the tonofilaments into keratin
- contains ________
- release lipid-rich secretion
- acts as a water-repellent sealant
- marks the transition between the deeper, metabolically active strata and the dead cells of the more superficial strata
A
STRATUM GRANULOSUM
- apoptosis
- keratohyalin
- lamellar granules
17
Q
- present only in the thick skin areas
- fingertips
- palms
- soles
- consists of 3-5 layers of flattened clear, dead keratinocytes that contain large amounts of keratin and thickened plasma membranes
A
STRATUM LUCIDUM
18
Q
- 25-30 layers of flattened dead keratinocytes
- continuously shed and replaced by cells from the deeper strata
- contains mostly keratin
- help to protect deeper later from injury and microbial invasion
- callus
- abnormal thickening of the stratum corneum
- due to constant exposure of skin to friction
A
STRATUM CORNEUM
19
Q
- New skin cannot regenerate if an injury destroys a large area of the stratum Basale and its stem cells.
- Skin wounds of this magnitude require this in order to heal.
- A ________ is the transfer of a patch of healthy skin taken from a donor site to cover a wound.
A
- skin graft
20
Q
- second, deeper part of the skin
- composed of a strong ______ tissue containing ______ and ______ which provides great tensile strength
- has the ability to stretch and recoil easily
- can be divided into 2 regions
A
DERMIS
- connective
- collagen and elastic fibers
a. superficial papillary region
b. deeper reticular region
21
Q
- consists of areolar connective tissue containing thin collagen and fine elastic fibers
- __________:
- small, fingerlike structure that project into the undersurface of the epidermis
- increases surface area
- contains capillary loops (blood vessels)
- _______: aka corpuscles of touch; nerve endings that are sensitive to touch
- _______: dendrites that lack any apparent structural specialization; initiate signals that give rise to sensations of warmth, coolness, pain, tickling, itching
A
superficial papillary region
- dermal papillae
- meissner corpuscles
- free nerve endings
22
Q
- attached to the subcutaneous layer
- consists of dense _________ tissue
- contains fibroblasts, bundles of collagen and some coarse elastic fibers
- spaces between fiber contain some adipose cells, hair follicles, nerves, sebaceous glands and sudoriferous glands
- provides the skin with strength, extensibility and elasticity
A
deeper reticular region
- irregular connective
- striae
- epidermal ridges
- fingerprints (footprints)
23
Q
o Stretchmarks
o Small tears in the dermis that is due to extreme stretching
o Visible as red or silvery white streaks on the skin surface.
A
striae
24
Q
o Produced during the third month of fetal development
o Downward projections of the epidermis into the dermis between the dermal papillae of the papillary region
o Increases the surface area of the epidermis and thus increase the grip of the hand or foot by increasing friction
A
epidermal ridges
- fingerprints
25
- The epidermal ridge pattern that is genetically determined and is unique for each individual
- Because ducts of sweat glands open on the tops of the epidermal ridges as sweat pores, the sweat and ridges form fingerprints upon touching a smooth object.
fingerprints (footprints)
26
- a common and chronic skin disorder in which keratinocytes divide and move more quickly than normal from the stratum Basale to the stratum corneum.
- shed prematurely un as little as 7 to 10 days.
- The immature keratinocytes make an abnormal keratin, which forms flaky, silvery scales at the skin surface, most often on the knees, elbows, and scalp (dandruff).
psoriasis
27
* indicate the predominant direction of underlying collagen fibers.
* The lines are especially evident on the palmar surfaces of the fingers, where they are aligned with the long axis of the digits.
lines of cleavage and surgery
28
The accessory structures of the skin include the hair, skin glands and nails which develop from the _____________.
They have a host of important functions.
For example, hair and nails protect the body, and sweat glands help regulate body temperature
- embryonic epidermis
29
- aka pili
- Present on most skin surfaces except palms, palmar surfaces of the fingers, soles and plantar surfaces of the feet.
Functions:
a. __________
- guards the scalp from injury and the sun’s rays
- decreases heat loss from the scalp
b. __________
- Protect the eyes from foreign particles
c. __________
- Sensing light touch
HAIR
a. Hair on the head
b. Eyebrows and eyelashes
c. Touch receptors
30
anatomy of the hair
a. shaft
b. root
- inner medulla
- middle cortex
- cuticle of the hair
c. hair follicle
- epithelial root sheath (external root sheath & internal root sheath)
- dermal root sheath [bulb - papilla of the hair & hair matrix]
d. arrector pili
e. hair root plexus
31
Composed of columns of dead, keratinized epidermal cells bonded together by extracellular proteins.
anatomy of the hair
32
- Superficial portion of the hair
- Projects above the surface of the skin
shaft
33
Portion of the hair deep to the shaft that penetrates into the dermis, and sometimes into subcutaneous layer.
root
- inner medulla
- middle cortex
- cuticle of the hair
34
Composed of two or three rows of irregularly shaped cells
inner medulla
35
Forms the major part of the shaft and consists of elongated cells
middle cortex
36
36
- Outermost layer
- Consists of a single layer of thin, flat cells that are the most heavily keratinized.
* Cuticle of the shaft
- Arranged like shingles on the side of a house, with their free edges pointing toward the end of the hair
cuticle of the hair
37
- Surrounds the root of the hair
- Made up of an epithelial root sheath
hair follicle
38
1. ____________
- Downward continuation of the epidermis
2. ____________
- Forms a cellular tubular sheath of epithelium between the external root sheath and the hair
1. External root sheath
2. Internal root sheath
39
- Dense dermis surrounding the hair follicle
dermal root sheat
40
- Onion shaped structure
- base of each hair follicle
bulb
- papilla of the hair
- hair matrix
41
o Nipple-shaped indention
o Contains areolar connective tissue and many blood vessels that nourish the growing hair follicle.
papilla of the hair
42
o Germinal layer of cells
o Arise from stratum Basale
o Responsible for the growth of existing hairs and they produce new hairs when old hairs are shed.
o Replacement process occurs within the same follicle
o Give rise to the internal root sheath
hair matrix
43
- It extends from the superficial dermis of the skin to the dermal root sheath around the side of
the hair follicle.
* in its normal position
- hair emerges at an angle to the surface of the skin.
* Under physiological or emotional stress, such as cold or fright
- autonomic nerve endings stimulate the arrector pili muscles to contract, which pulls the hair shafts perpendicular to the skin surface.
- This action causes “goose bumps” or “gooseflesh” because the skin around the shaft forms slight elevations.
arrector pili
44
- Dendrites of neurons
- Sensitive to touch
- Generate nerve impulses if their hair shafts are moved.
hair root plexus
45
_________: substance that removes hair
- It dissolves the protein in the hair shaft, turning it into a gelatinous mass that can be wiped away.
- hair root is not affected, regrowth of the hair occurs.
- depilatory
46
In _________, an electric current is used to destroy the hair matrix so the hair cannot regrow.
Laser treatments may also be used to remove hair.
electrolysis
47
HAIR GROWTH
a. growth stage (anagen)
b. regression stage (catagen)
c. resting stage (telogen)
48
- Where cells of the hair matrix divide.
- As new cells from the hair matrix are added to the base of the hair root, existing cells of the hair root are pushed upward, and the hair grows longer.
- While the cells of the hair are being pushed upward, they become keratinized and die.
growth stage (anagen)
49
When the cells of the hair matrix stop dividing, the hair follicle atrophies (shrinks), and the hair stops growing.
regression stage (catagen)
50
- a new growth cycle begins
- The old hair root falls out or is pushed out of the hair follicle, and a new hair begins to grow in its place.
resting stage (telogen)
51
_________: treatment of disease, usually cancer, by means of chemical substances or drugs
_________: interrupt the life cycle of rapidly dividing cancer cells.
- the drugs also affect other rapidly dividing cells in the body, such as the hair matrix cells of a hair.
- It is for this reason that individuals undergoing chemotherapy experience hair loss.
- chemotherapy
- chemotherapeutic agents
52
TYPES OF HAIRS
1. lanugo
2. terminal
3. vellus
53
- Appears usually by the fifth month of development
- Very fine, non-pigmented, downy hairs that cover the body of the fetuses
lanugo
54
- Long, coarse, heavily pigmented hairs
- Prior to birth, the lanugo of the eyebrows, eyelashes and scalp are shed and replaced by this type of hair
terminal hairs
55
- Commonly called “peach fuzz"
- short, fine, pale hairs that are barely visible to the naked eye.
- Lanugo of the rest of the body are replaced by this type of hair
vellus hairs
56
- synthesized by melanocytes scattered in the matrix of the bulb and passes into cells of the cortex and medulla of the hair.
a. ________: dark hair color
b. ________: blond and red hair
- Hair becomes gray because of a progressive decline in melanin production
o gray hair contains only a FEW melanin granules
o White hair results from the LACK of melanin and the accumulation of air bubbles in the shaft.
- MELANIN
a. eumelanin
b. pheomelanin
57
SKIN GLANDS
a. sebaceous gland (oil)
b. sudoriferous gland (sweat)
c. ceruminous gland
58
- simple, branched acinar glands
- secreting portion of a sebaceous gland lies in the dermis and usually opens into the neck of a hair follicle.
- In some locations, such as the lips, glans penis, labia minora, and tarsal glands of the eyelids, this open directly onto the surface of the skin.
- Absent in the palms and soles
- small in most areas of the trunk and limbs, but large in the skin of the breasts, face, neck, and superior chest.
sebaceous glands
- sebum
59
o a mixture of ________, ________, ________, ________
o coats the surface of hairs and helps keep them from drying and becoming brittle.
o prevents excessive evaporation of water from the skin, keeps the skin soft and pliable, and inhibits the growth of some (but not all) bacteria.
sebum
- triglycerides, cholesterol, proteins, and inorganic salts
60
- During childhood, sebaceous glands are relatively small and inactive.
- At puberty, ________ from the testes, ovaries, and adrenal glands stimulate sebaceous glands to grow in size and increase their production of sebum.
- _______: an inflammation of sebaceous glands that usually begins at puberty, when the sebaceous glands are stimulated by andro- gens.
- androgens
- Acne
61
- acne occurs predominantly in sebaceous follicles that have been colonized by bacteria, some of which thrive in the lipid-rich sebum.
- The infection may cause a cyst or sac of connective tissue cells to form, which can destroy and displace epidermal cells.
- This condition, called ________, can permanently scar the epidermis.
- Treatment consists of gently washing the affected areas once or twice daily with a mild soap, topical antibiotics (such as clindamycin and erythromycin), topical drugs such as benzoyl peroxide or tretinoin, and oral antibiotics (such as tetracycline, minocycline, erythromycin, and isotretinoin).
- Contrary to popular belief, foods such as chocolate or fried foods do not cause or worsen acne.
- cystic acne
62
- cells of these glands release sweat, or perspiration, into hair follicles or onto the skin surface through pores.
- glands are divided into two main types: ______ & ______
SUDORIFEROUS GLANDS (SWEAT)
1. eccrine
2. apocrine
63
- Throughout skin of most regions of the body, especially in skin of forehead, palms, and soles
- Mostly in deep dermis
- Surface of epidermis
- Less viscous; consists of water, ions (Na+ , Cl-), urea, uric acid, ammonia, amino acids, glucose, and lactic acid.
- Regulation of body temperature, waste removal, and stimulated during emotional stress.
- Soon after birth
ECCRINE SWEAT GLANDS
64
- Skin of the axilla, groin, areolae, bearded regions of the face, clitoris, and labia minora
- Mostly in subcutaneous layer
- Hair follicle
- More viscous; consists of the same components as eccrine sweat glands plus lipids and proteins
- Stimulated during emotional stress and sexual excitement
- Puberty
APOCRINE SWEAT GLANDS
65
- produce a waxy lubricating secretion.
- secretory portions of ceruminous glands lie in the subcutaneous layer, deep to sebaceous glands.
- excretory ducts open either directly onto the surface of the external auditory canal (ear canal) or into ducts of sebaceous glands.
CERUMINOUS GLANDS
- cerumen (ear wax)
66
o The combined secretion of the ceruminous and sebaceous glands
o A yellowish material
o Provides a sticky barrier that impedes the entrance of foreign bodies and insects
o Waterproofs the canal and prevents bacteria and fungi from entering cells
cerumen (earwax)
